674 " THETIS " SCIENTIFIC RESULTS. 



secondary bi anches which ran parallel to one another. As the.se 

 secondary branches are nearly as thick as the main branch from 

 which they spring, the effect of a repeated dichotomy is produced, 

 an effect that is heightened by the tendency of the main branch 

 to bend outwards after each branch is given off, so that its course 

 describes a series of shallow curves. The secondary blanches 

 rise straight upwards and may remain unbranched throughout 

 their length, or may divide dichotomously. Branching is strictly 

 in one plane. 



The polyps are arranged in close spirals all over the larger 

 colonies, though one young specimen shows the polyps in a 

 single altercating row on each side of the branch. 



The polyps are club-shaped, with truncated mouths ; they are 

 directed upwards, and bent towards the stem. In the largest 

 speciuien the upper parts of the polyps have all been rubbed off, 

 which produces a deceptive appearanee of very short, truncate 

 polyps with their mouths directed outwards from the stem. 



There is a considerable variety in the spicules (PI. Ixvii. fig. 1). 



(1) There are somewhat flattened, curved spindles, produced 

 on the convex side into a number of sharp, prominent teeth. The 

 following measurements were taken of length and breadth in 

 millimetres.— -238 X -102; -187 x -085 ; -118 x -068; -102 x -051. 



(2) Spicules of similar form to (1), but simpler and with only 

 a few small warts.— -153 x -051 ; -136 x -053 ; -102 x -034 mm. 



(3) Small " Blattkeulen " with a very small shaft, bearing 

 sometimes a few warts, and supporting a group of sharp, blade- 

 like projections. — >102 x -085 ; -09 x -068 ; -051 x -032 mm. 



(4) Small irregular bodies and " capstans." — -085 x "085 ; "102 

 X 0-85; 0-68 X U-51 ram. 



The colour of the colonies is pale-brown to cream. 

 Previously recorded from the Indian Ocean, and Port Jackson, 

 New South Wales, 35 fathoms. 



MOPSEA. ENCRINULA, Lamarck. 



Mopsea encrinula, Wright and Studer, Chall. Eep., Zool., xxxi., 

 1889, pp. 43-44, pL vii., figs, 1, 1% P., pi. ix., fig 11. 



Stations 34, 44, 47. 



A few incomplete specimens in the present collection agree 

 closely with the description of Mopsea encrinula (Lamarck), given 

 by Wright and Studer. Branching is plume-like in one plane ; 

 the club-shaped polyps, 1 mm. long, cover the branches and twigs 

 in a close spiral, and are incurved towards the stem. Many of 

 the spicules are yellow and white flattened spindles, approaching 

 the "lancet-shaped plates" of Wright and Studer's description. 



